Preparation of sulphonic acids



Nov. 1s, 1941. 'A LAZAR ETAL 2,263,041

PREPARATION OF SULPHQNIC ACIDS Original Filed March 30, 1958 y-P/aooucrRECOVERY FROM ,4c/0 omc/0G56 Arial J/udgc frflacf A Traag/v1.51?"rwtion, extreetiony end pnriiioation which may be produced in which theconcentration of acid tar pure sulphonic eoids utilizing only standardmetal To illustrate the increase inV concentration of equipment.sulphonic acids which remaindissolved in the The type of hydrocarbonoil, which may be used 30 oil, with progressive applications ofincrements of as the starting point of the sulphonation procacid, thefollowing data. are given: i ess, is governed commercially solely by thenecessary qualification that appropriate yields of pmenim. sulphonicacids can be obtained therefrom by sul- Increment p ouioooi s4phonation, but the processis broadly applicable 35 numb Quantity am Seddkienmhitn to the production of sulphonic acids from all sulthe "u`UNITED STATES PATENT OFFIE PREPARATION F SULPHONIC ACIDS ArthurLazarand Paul Moritz Ruedrieh, Berkeley, Calif., asslznors to Tide WaterAssociated Oil Company, San Francisco, Calif., n corporation of Delawareoriginel application Maren so. 193s. sei-iai ne. 193,916. Divided andini. application april 1s, 193s, sei-ienne. zessen i n 1s claims. (ci.zoo- 504) This invention relates to thel preparation and For thesulphonationof the base oil concenpurificatlon of sulphonic acids. dtrated sulphuric acid is recommended,V however,

An object is to provide `o. process whereby acid Other SulDhOnatingagents may be used. For exsludges may be treated to recover sulphonicacids ample. chlOrOSlllDhOnic acid. 0r Sulphurc acid in and othervaluable {3y-products therefrom. 5 Conjunctin with Certain Waterabsorbing ingreother objects of invention `will be apparent dients. Suchas phosphorous pentoxide, may be as the subject isnioi-e fullydisclosed, used to aid the vsulphonation process. By con- The usualprocesses of preparation and purieentrated Sulphuric acid, 66 B. up to50% fumflcation of sulphonic acids involve the sulphonaing SlllDhlllieaeid 1S menne;` hOWeVer an acid tion of reactive hydrocarbons in oilswith fum- 10 Strength 0f 5 t0 20% filming sulphuric acid is ingsulphuric acid, the neutralization of sulphonic Drefenedacids formedwith an alkaline reagent and the In the SUlphOnB-tion 0f the raillnatethe acid separation and purication of such acids over, iS Preferablyadded in increments of from 5 to their metal seits, pounds per barrel ofoil. 'I'he rst few in- By vthis is meant that the sulphonic `acids arecrements attack oil constituentswhich are easily extracted as watersoluble alkali salts, the latter sulphonted OXdiZed 0r polymerized andrebeing converted to less soluble alkaline earth metmove them eS a terrymass in the acid sludge. al salts, whichfthen can be purified by eitherre- Through theinitial removal of such constituents, crystallization orany other conventional means. Cid Sed in Subsequent increments 1S notSpent From the purified seits, the pui-e suiphonio acids in sidereactions, but is directed in substantially then can be isolated byacidification with mineral full Strength ir'OWaIdS the SulphOnation ofhydroeoids, n f i carbons to yield sulphonic acids. By the use of Thisinvention provides,` s, process of preparaacid in increments thereforeacid sludges can be applied to the production of al1 types of sulphonicy 25 progressively decreases while the concentration acids, one of theadvantages of such process of sulphonic acids which remain dissolved inthe is that it permits the preparation of substantially Oilincreasesphonatable hydrocarbon oils, such as may ini- Such base oilfraction may be sulphonateddioi sulphonic acids in theoilis increased,the sulrectly or may be first subjected to treatment by phnating etOn 0fthe'slllphule Aacid gradually a solvent refining process, such as iswell known decreases. In other words, the sulphonation in the luse ofliquid sulphur dioxide, furfurai, process slackensand the efficiency ofthe treatbenzol-sulphur dioxide, phenol, cresylic acid, di` ing reagentdecreases, in proportion to the Vaccuchlorethylether, or by other wellknown solvent i' 0 mulatin 0f SillDhOneted Components in the Oilreflningprocesses, whereby an extract isremoved F01' this reaSOnit iS Often`Preferred t0 remeve therefrom. 'I'he material which is insoluble in thesulphonic acids, after their concentration has the selective solventwill hereafter be termed reachedabout 5% by Weight, aS an intermediateraflinate, and is -an oil which ispreferably the `processing step.`Suchremoval can be accomraw materialuSedfOrsuIphonatiOn. plished byneutralization with an alkali, thus converting the sulphonic acids intosoaps. It is preferred, however, to accomplish such removal by theprocess shown in Vour copending application now U. S. Patent Number2,218,174.

By using this step procedure of alternate sulphonation and removal ofsulphonated products, thevadvantages are:

1. Better utilization of the treating agent.

2. Increased yields of sulphonic acids.

3. A segregation of sulphonic acids according to types, as explained indetail below.

This procedure is highly recommended in the manufacture of technicalwhite oils and medicinal type oils, or any other type of Ihighly refinedmineral oil. As as example, it is possible to obtain a water whiteodorless and non-iluorescent oil by treatment with considerably lessacid by this step procedure, than by the procedure in which theintermediate removal of sulphonated products is omitted.

Our process, however. is so exible that it may be appied to acid oilscontaining sulphonic acids or acid'sludges irrespective of the means ormanner of adding the sulphonating agent. The use of increments of acidis preferred largely for ease of operation in that it effects apartialpreliminary isolation of chemical constituents.

The total quantity of acid which may be used may vary up to 100 percentby volume but in most instances 1.5 to by volume is used. After severalincrements of acid are applied the acid produces sulphonic acids whichare predominately of the oil soluble type.

The temperatures employed in the above described application ofsulphuricv acid are regulated to produce the desired sulphonation. Whenrelatively low rates of acid are employed the maximum sulphonatingtemperature is held to below about 130 F. After an initial applicationof acid and withdrawal of sludge the sulphonation of the residual oilmay be performed at temperatures up to 350 F.. but temperatures shouldbe avoided at which the sulphuric acid usually acts as an oxidizingagent.

In the practice of the invention, the preparation of sulphonic acids andother by-products may often be' profitably combined with the relining.of a lubricating oil fraction. In so doing just sumcient acid isemployed to suitably reilne the oil and produce an equivalent quantityof sulphonic acids. When such treatment is perprocess ei er undiluted orin aqueous solutions. A few of ose which are suitable are:

ethyl alcohol Ethyl alcohol Propyl alcohols Ethylene glycol GlycerolHexahydric alcohols Acetone Oxides Dioxan Alcohols...-

i Este {Ethylene glycol acetate Diethylene glycol acetate ers {Methylether of ethylene glycol Ethylether of ethylene glycol Ether-esters---Ethyl ether of diethylene glycol acetate A1dehydes {FormaldehydeAcetaldehyde Ethylene chlorhydrin Cmhydnsf-{Dietnylene cmorhyarm It isadvantageous not to use aqueous solutions of solvents for sludgetreatment. Further, of

the solvents, methyl alcohol is preferred because it not only serves thefunction of extracting substantially allthe sulphonic acids and leavingundissolved tarry matter behind, but it is also particularly amendableto recovery due to its low boiling point.

The methyl alcohol is added to the acid sludge and thoroughly mixedtherewith. through efficient agitation as for example by a mechanicalmixing device. lI'his operation may be performed at any temperature atwhich the solvent remains liquid, temperatures above atmosphericimproving contact between acid sludge and the extracting medium. After asuitable period of agitation the mixture is permitted to stand andseparate into layers. 'I'he upper, or methyl alcohol layer, is thendecanted from the tarry material. Several applications of solvent areapplied in order formed there is produced (1) an acid oil containingfree sulphonic acids (2) acid sudges isolated in increments. 'Ihe acidsludgesare processed separately and such steps are further set forth indetail, which are illustrated as diagrammatic flow sheet in theaccompanying drawing, merely as an aid in following the text of thespecification.

Treatment of acid sludges to remove substantially all the methyl alcoholsoluble ingredients from the tarry material. At this point in theprocessing there is produced (1) a methyl alcohol extract, (2) a tarryresidue.

The methyl alcohol extract contains sulphuric acid, polymerization andcondensation products, sulphonic acids, and other acidic organic sulphurcompounds. This extract is distilled, as for example, under vacuum, andthe methyl alcohol removed for reuse. The material in the still, whichis termed residue #l in the figure, is then extracted with an organicsolvent which will dissolve the sulphonic acids and leave the sulphuricacid undissolved. Aliphatic hydrocarbon solvents are applicable, andsuch as have low boiling points are preferred. Examples of solvents arepropane, butane, and petroleum ether. The use of solvents like liqueedpropane or butane is advantageous because, after extraction isaccomplished and the solvent decanted, the latter may be separated bydistillation .at a low temperature.

For thepurpose of illustration there is shown, in the figure, anextraction of residue #l with petroleum ether. After the stratificationof layers the solvent extract is decanted oi'l' leaving residue #2. Tofacilitate lthe description, the processing o f (l) residue #2, (2) thesolvent extract will be discussed separately.

Residue #2 contains the bulk of the sulphuric acid and organic materialssuch as acidic sulphur compounds. This residue is extracted with anaromatic solvent whereby substantially all the l 27,203,041 organicmatter is dissolved and` removed in the solvent leaving the sulphuricacid;` (residue which; due to the removalf'of organic matter., is inconditionfto be recovered by well known acid: recovery methods. Thearomatic solvent extract is neutralized with an aqueous alkaline reagentand permitted toV separate. into layers. The ,lower or aqueous layercontains soaps of acidic organic sulphur compounds' which have excellentemulsifying properties. i

The petroleum ether extract' derived in the treatment of residue #l is`distilled 'and the solvent recovered for reuse, leaving in the stillresidue #3. The latter is-largely sulphonic acids and non-acidic organicmatter. This residue is extracted with water whereby the ilnal,separation of the sulphonic acids is accomplished. The water extractcontains the pure sulphonic acids and the oily residue (residue #4) islargely polymers and resins. Pure sulphonic acids are produced when thewater is removed.' e.v g., by distillation, with or without vacuum.

By referring to the figure the processing steps can be easily followed.The treatment of the acid sludges as above described has resulted so farin the isolation of a number of valuable byproducts as:

Pure sulphonic acids.

Polymers and resins.

Acidic sulphur compounds which have excellent emulsifying properties.

Sulphuric acid of substantial purity which is amenableto acid recoverydue to the separation of organic matter therefrom.

Up to this point the methyl alcohol soluble portion of the acid sludgehas been dealt with. The tarry material which had `been left aftertheremoval of the methyl alcohol extract is now processed for thefurther recovery ofvaluable by-products. The material is subjected to akhydrolizing treatment with steam or hot water. By repeated applicationsoi' hotwater the sulphuric acid; formed by hydrolysis of the sulphur'-ic acid esters, is removed, leaving a semi-solid residue (residue #6).

Residue #5 is extracted with a solvent, such as petroleum ether and allmaterial soluble in such solvent removed. The semi-solid material(residue #7) which is insoluble in petroleum ether is neutralized withdilute alkali and found to be an excellent emulsifying agent.

The petroleum ether extract is washed with a. dilute'alkali to removetraces of acidic impurities and, after separation of the aqueous alkali,the extract is distilled. "I'he petroleum ether, thus. removed, isreused. The still residue (resi-V due #8) is extracted with acetonewhereby all acetone soluble constituents are removed in an extract.After separation of the solvent, byL distillation, the acetone solublematerial is found to be a soft, viscous, neutral material which, due toits compatability characteristics, is valuable as a plasticizer` or, isuseful in special lapplica.- tions. as for example, as a pigment vehiclein printer's ink.

The acetone insoluble `material has the property of being soluble inpetroleum and aromatic hydrocarbons.. It is a hard, plastic solid whichis of value as a coating material or maybe used in lacquers byincorporation with resins, drying oils, or semi-drying oils, to impartfilm forming characteristics tothe combination.`

As in the processing of the methyl alcohol soluble constituents oftheacid sludge, the treatment of the tarry residue from such extractionconcentrations of sulphonic acids.

also yields valuable by-products. For example, the following productsgare obtained:

A 8004 emulifying agent.' f i A hard and 4thermoplastic resin which issoluble in petroleum hydrocarbons;

A soft, viscous, neutral material, valuable for use as a plasticizer andwhich is compatible with nitrocellulose solutions.

The process shown in the ligure is quite complete and by means ofrepeated extractions with suitable solvents and other requiredprocedures, a separation of acid sludges into a large number of valuableby-products is effected.

In the description of the initial steps of the process, e. g., thesulphonation step, it was stated that a partial separation of chemicalconstituents resulted from the addition of the sulphonating agent inincrements. Through such use of increments it is possible to produceacid oils and acid sludgeswhich contain a preponderance of one type ofreaction products. Further by such preliminary segregation subsequentprocessing steps and the recovery of by-products, are facili-` tated. Itis also found that while sulphonating, if the temperature as well asacid concentration is controlled, acids of different molecular weightmay be isolated.

To illustrate: The base oil is treated'with sulphuric acid of from 93%H2304 up to 50% fuming acid at normal temperatures, starting at say 70F., and the temperature maintained within a range of about -20 F. bysuitable control means. After the ilrst two or three increments the acidoil is treated to remove sulphonic acids contained therein. The oil isagain treated with fuming acid and the sulphonic acids extracted fromthe oil. In this manner a series of acid sludges and a series of solventextracts of sulphonic acids is obtained, thus accomplishing a selectivesulphonation of thehydrocarbons. For example, the first few acid sludgeswill contain a good proportion of acid tar and only a relatively smallamount of sulphonic acids. 'Ihese are processed to recover valuableby-products as described in the ligure. 'I'he ylater sludges will havehigher Of these sludges the iirst in which sulphonic acids predominatewill yield acids of a different average molecular weight than sludgesproduced several acid increments later. Such a feature is due to o thefact that the ilrst sulphonic acids are produced from hydrocarbons whichare more readily` attacked whereas after removal of such hydrocarbonsthe acid must thenattack the more difilcultly sulphonated hydrocarbons.In ythe 'two cases the sulphonic acids produced will be of dif# ferenttype with respect to the structure ofthe organic radical. Similarly theVarious solvent extracts, containing sulphonic acids which had beenremoved from the oil after each acid treat, willhave different types ofsulphonic acids in solution.

lWhen the yield of sulphonic acids at the first controlled temperatureand S03 concentration becomes small.l the treating temperature and/crS03; concentration are raised and the process re-` peated, againcontrolling the temperature within-v about 20 F. range. By suchtemperature and concentration control and by the addition of acidv inincrements progressive sulphonation of hydro-i fcarbonsttakes place'.Hence by the isolation of acid sludges and solvent extracts in steps andthe separate recovery of sulphonic acids therefrom `sulphonic AacidsA ofdifferent average molecular which comprises: treating a petroleum oilwith a sulphonating agent/removing the sulphonating agent with itscontained sulphonic acids and other products, extracting said sulphonicacids with an organic oil insoluble solvent, separating said solventfrom said products and sulphonic acids, then extracting said sulphonicacids and non-acidic compounds from said other products with a lowboiling aliphatic hydrocarbon solvent, removing said aliphatichydrocarbon solvent, separating said sulphomc acids and non-acidiccompounds, and separately recovering said sulphonic acids.

2. The process of preparing sulphonic acids which comprises: treating apetroleum oil with aA sulphonating agent, removing the sulphonatingagent with its contained sulphonic acids and other products, extractingsaid 'sulphonic acids with methyl alcohol, separating said solvent fromsaid products and sulphonic acids, then extracting said sulphonic acidsand non-acidic compounds from said other products with a low boilingaliphatic hydrocarbon solvent, removing said aliphatic hydrocarbonsolvent, separating said sulphonic acids and non-acidic compounds, and

separately recovering said sulphonic acids.

3. The process of preparing sulphonic acids which comprises: treating apetroleum oil with a sulphonating agent, removing the sulphonating agentwith its contained sulphonic acids and other products, extracting saidsulphonic acids with anhydrous methyl alcohol, separating said solventfrom said products and sulphonic acids, then extracting said sulphonicacids and nonacidic compounds from said other products with a lowboiling aliphatic hydrocarbon solvent, removing said aliphatichydrocarbon solvent, separating said sulphonic acids and non-acidiccompounds, and separately recovering said sulphonic acids.

4. 'I'he process of preparing sulphonic acids which comprises: treatinga petroleum oil with a sulphonating agent, removing the sulphonatingagent with its contained sulphonic acids and other products, extractingsaid sulphonic acids with methyl alcohol in a plurality of steps,separating said solvent from said products and sulphonic acids, thenextracting said sulphonic acids and non-acidic compounds from said otherproducts with a low boiling aliphatic hydrocarbon solvent,` removingsaid aliphatic hydrocarbon solvent, separating said sulphonic acids andnonacidic compounds, and separately recovering said sulphonic acids.

5. The process of preparing sulphonic acids which comprises: extractingan acid sludge containing sulphuric acid, sulphonic acids, organicsulphur compounds, polymers, resins, and tarry matter with an organicoil-insoluble solvent whereby the sulphuric acid, sulphonic acids,organic sulphur compounds, polymers and resins are dissolved and thetarry matter remains undissolved; separating theA solvent solution fromthe undissolved tarry matter; evaporating the solvent from theconstituents dissolved therein;

rextracting saidconstituents with a low boiling aliphatic hydrocarbonsolvent whereby the sulphonic acids, polymers, and resins arev dissolvedand the sulphuric acid vand organic sulphur compounds remainundissolved; evaporating said aliphatic hydrocarbon solvent from saidsulphonic acids, polymers, and resins; and extracting the sulphonicacids from the polymers and resins with water. f

6. The process according to claim 5in which the organic oil-insolublesolvent is methyl alcohol.

7. In a process wherein valuable products are obtained from acid sludgeresulting from the treatment of petroleum oil with a sulphonating agent,the steps which comprise: extracting an acid sludge containing sulphuricacid, sulphonic acids, and tarry matter wlthan organic oil-insolublesolvent whereby the sulphuric acid and sulphonic acids are substantiallydissolved and the tarry matter remains substantially undissolved, andthen separating the resulting solvent solution from the undissolvedtarry matter.

8. The steps according to claim 7 in which the organic oil-insolublesolvent is methyl alcohol.

9. In a process wherein valuable products are obtained from acid sludgesresulting from the treatment of petroleum oil with a sulphonating agent,the combination of steps which comprises: extracting an acid sludgecontaining sulphuric acid, sulphonic acids, organic sulphur compoundsand tarry matter with an organic oil-insoluble solvent whereby thesulphuric acid, sulphonic acids, and organic sulphur compounds aresubstantially dissolved and the tarry matter remains undissolved;separating the resulting solvent solution from the undissolved tarrymatter; evaporating the solvent from the solution; and separating thesulphonic acids from the resulting mixture by extraction with a lowboiling aliphatic hydrocarbon solvent.

10. The process of preparing valuable products from acid sludgesresulting from the treatment of petroleum oil with a sulphonating agentwhich' comprises: extracting an acid sludge containing sulphonic acids,sulphuric acid, and tarry matter with an organic -oil-insoluble solventwhereby the sulphonic acids and sulphuric acid are dissolved and thetarry matter remains undissolved; separating the resultant solventsolution from the undissolved tarry matter; hydrolysing said tarrymatter; extracting the hydrolysed tarry matter with a light petroleumsolvent leaving a residue; and then removing and saponifying saidresidue.

1l. The process of preparing valuable products from acid sludgesresulting from the treatment of petroleum oil with a sulphonating agentwhich comprises: extracting an acid sludge containing sulphonic acids,sulphuric acid, and tarry matter with an organic oil-insoluble solventwhereby the sulphonic acids and sulphuric acid are dissolved ,and thetary matter remains undissolved; separating the resultant solventsolution from the undissolved tarry matter; hydrolysing said tarrymatter; extracting the hydrolysed tarry matter with a light petroleumsolvent leaving a residue; removing said residue from the solventsolution; evaporating the solvent to obtain a second residue and thenextracting said second residue with acetone to obtain a thermo-plasticresin as a third residue.

12. The process of preparing valuable products from acid sludgesresulting from the treatment of petroleum oil with a sulphonating agentwhich comprises: extracting an acid sludge containing sulphonic acids,sulphuric acid, and tarry matter with an organic oil-insoluble solventwhereby the sulphonic acids and sulphuric acid are dissolved and thetarry matter remains undissolved; separating the resultant solventsolution from the undissolved tarry matter; hydrolysing said tarrymatter; extracting the hydrolysed tarry mattei` with a light petroleumsolvent leaving a residue; removing said residue from the solventsolution; evaporating the solvent solution to obtain a second residue;extracting said second residue with acetone to obtain a third residue;removing said third residue from the acetone solution; and evaporatingsaid acetone solution to obtain a plasticizer therefrom.

13. The process of preparing valuable products from acid sludgesresulting from the treatment of petroleum oil with a sulphonating agentwhich comprises: extracting an acid sludge containing sulphuric acid,sulphonic acids, organic sulphur compounds, polymers, resins, and tarrymatter with an organic oil insoluble solvent whereby the sulphuric acid,sulphonic acids, organic sulphur compounds, polymers and resins aredissolved and the tarry matter remains undissolved; separating thesolvent solution from the undissolved tarry matter; evaporating thesolvent from the constituents dissolved therein; extracting saidconstituents with a low boiling aliphatic solvent whereby the sulphonicacids, polymers, and resins are dissolved and the sulphuric acid andorganic sulphur compounds remain undissolved; separating the solventsolution from the undissolved matter; extracting said undissolved matterwith an aromatic hydrocarbon solvent to form a solvent layer and asulphuric acid layer; treating the solvent layer with aqueous alkali;and separating the resultant aqueous layer.

14. The process of purifying acid sludges for the recovery of sulphuricacid which comprises: extracting an acid sludge containing sulphuric apetroleumoil with a sulphonating agent in a series of increments toprovide sulphonic acids dissolved in the sulphonating agent, increasingthe temperature of treatment with each increment, removing the spentsulphonating agent and dissolved sulphonic acids after each increment,extracting said sulphonic acids from said sulphonating agent with anoil-insoluble organic solvent after each increment, and recovering thesulphonic acids from said solvent.

16. The process of preparing sulphonic acids from hydrocarbon oils whichcomprises: treating a petroleum oil with a sulphonating agent inV aseries of increments to provide sulphonic acids dissolved .in thesulphonating agent, increasing the temperature of treatment with eachincrement, removing the spent sulphonating agent and dissolvedsulphonicv acids after each increment, extracting said sulphonic acidsfrom said sulphonating agent with an oil-insoluble organic solvent aftereach increment, extracting said sulphonic acids from said solvent with alow boiling aliphatic hydrocarbon solvent, and recovering the sulphonicacids from said aliphatic hydrocarbon solvent.

ARTHUR LAZAR.

PAUL MORITZ RUEDRICH.

